Introduction

DeepSeek Harness (DSH) uses a modular architecture and allows functionality to be extended through plugins. In the area of reasoning models, adjusting reasoning effort is a common requirement, and both Codex and Claude Code provide dedicated sliders for this purpose. DSH does not integrate this feature natively, which is why the plugin-effort-slider plugin exists. It combines the model selector and the reasoning effort slider into a single control and embeds it directly in the composer area where the input box is located.

Core Features

This plugin provides the following interaction improvements:

  • Unified pill-shaped container: The model selector and slider share one bordered pill-shaped container, separated by a divider. The slider sits right next to the model name.
  • Simplified model list: When the model name is clicked, the list skips submenus and directly displays all providers and models, while the slider remains visible.
  • Notched slider: It uses notches instead of smooth dragging, with each notch corresponding to an actual reasoning level for the model (typically 2-7 levels). Keyboard navigation is supported (arrow keys, Home, End).
  • Top gradient effect: When the slider is pushed to the top notch, the bar chart changes into a moving gradient effect, simulating DSH’s native “Deep diving…” blinking animation.
  • Theme following: All colors inherit from DSH variables, including the accent color of the send button. It adapts to light, dark, and future theme plugins.
  • Layout optimization: When the pill expands, the context ring moves to the end of the statistics row to avoid squeezing the send button; the input box height increases accordingly.
  • Zero core dependencies: The plugin consists of a single folder, and after uninstallation, DSH automatically removes the related styles and logic.

Installation

The DSH web profile is required. The installation command is as follows:

dsh plugin --profile web add github:mrSutivu/plugin-effort-slider

After installation, run dsh web to restart the web profile once, and refresh the page to activate it.

Usage

  1. Select a model that supports reasoning effort in the pill-shaped container.
  2. Drag the slider and release it; the adjustment takes effect when released.
  3. Push the slider to the top notch to trigger the gradient animation.
  4. If the current model does not define reasoning levels, the pill is automatically hidden, restoring DSH’s native selector.

Limitations and Notes

  • Runtime environment: Only the web profile is supported; it is a pure client-side UI plugin.
  • Model requirements: The pill is only displayed for models that expose reasoning levels. If a model is not supported (for example, it lacks low/medium/high levels), the plugin automatically hides.
  • Permissions: The plugin does not request host permissions, credentials, network calls, or external services.
  • Tested version: Tested successfully on DSH 0.1.2-alpha.